edit: this does not work on the next Qubes release (R4.1) (see here)
Whisker menu is awesome (compared to the default XFCE one) and it doesn’t even have to be installed (it’s already there)
I think it’s comes already be installed on the system. So you can follow the following guide (from the Add the Whisker menu to your XFCE panel
part only)
Replacing logo
Then you can also replace the “whiskers” icon with the qubes icon. Right-clicking on the whisker menu icon » properties » Icon
And then at the top of the window that pops up you select Location Icons
and then there should be 4 little “Q” icons (blue, green, red and yellow/orange).